This is like a sweet potato custard and you will want to take care not to over bake the filling. Check it frequently as it nears the end of its baking time and remember that it will set up a bit as it cools.

Pierce the sweet potatoes at each end with a fork and place them on a foil-lined baking sheet. Roast until the potatoes are soft, about 1 hour, turning them over halfway through the baking time. Cool, peel, and put the flesh through a food mill or mash smoothly with a potato masher. You should have 2 cups of puree.

Turn oven down to 375 degrees.

Combine the puree with all the remaining ingredients for the filling. Whisk until well combined and smooth. Pour the filling into the partially baked pie shell. Bake for about 45 to 50 minutes, until the filling is just barely set. When the rim of the pie shell is nudged, the very center of the filling should barely move.

Cool the pie to room temperature. It can be made several hours or up to 1 day in advance.

Notes:

* For a parve version, we suggesting using a parve liquid cream substitute such as MimicCream or Rich Whip

Place the flour, salt and sugar in the bowl of a food processor with a steel blade. Pulse to combine.

Add the chilled butter and shortening; pulse until the fat is evenly cut in and the mixture resembles coarse cornmeal . Remove to a mixing bowl.

Working quickly, gradually add enough cold water, while tossing and stirring with a fork, until the dough just begins to come together. Divide the dough into 2 even portions, flatten into rounds, wrap in plastic, and chill for a few hours or overnight.

Roll out 1 portion and fit it into a 9-inch pie pan. Crimp edges. Reserve remaining portion for another use. Line shell with foil or parchment paper and fill with dry rice or beans. Blind bake in a preheated 375 degree F oven for 20 minutes. Remove foil and beans before filling.